1. Field of the Invention
The present invention is directed to a magazine for carrying a plurality of data carriers, such as magnetic tape cartridges, of the type insertable in a loading device having a data reader, for selective removal of one of the data carriers from the magazine for use in said reader.
2. Description of the Prior Art
It is known to record and store data on a number of different types of storage media, such as magnetic tape, optical disks and the like. Because of the limited size of such data carriers, the amount of data which can be stored thereon is similarly limited. In computing and data retrieval systems wherein a large amount of data is stored, a relatively large number of such data carriers are required in order to contain all of the necessary data. To retrieve the data from the data carrier, it is necessary to insert the carrier into a data reader, such as a tape drive unit. (As used herein, the unit into which the data carrier is inserted will be referred to as a "reader," although it may also be used for the purpose of writing data on the carrier.)
In systems requiring multiple data carriers, it is cumbersome to manually successively insert and remove the data carriers from the reader. Many such systems, therefore, employ a data carrier magazine, which holds a large number of data carriers, with the magazine being loadable into a device which contains the reader. A selected data carrier can then be removed from the magazine, and inserted into the reader wherein the data on the carrier is read, or new data is written on the carrier. After the completion of the read or write operation, the data carrier is then automatically removed from the reader and is replaced in the magazine. The device which removes the data carrier from the magazine, inserts it in the reader, and removes it from the reader and replaces it in the magazine is generically known as a "loader." Loaders can generally be classified into three types: those in which the magazine is stationary in the loader and the drive is moved over the magazine to the position of a selected data carrier in the magazine, those wherein the reader is stationary and the magazine is moved to position a selected tape at a location for insertion in the reader, and those wherein both the magazine and the reader are stationary, and an "elevator" or other type of data carrier transfer mechanism is used to remove a selected data carrier from the magazine, transport it to, and insert it in the reader. Various combinations of these three basic types of units are also known.
The configuration of the magazine used in a particular system is, to a certain extent, dictated by the structural details of the loader in which it will be used. A magazine for tape cartridges is disclosed in U.S. Pat. No. 5,182,687, for example, which is designed to move vertically in a loader relative to a horizontally disposed reader. A tray-type magazine for magnetic tape cassettes is disclosed in U.S. Pat. No. 3,561,004 having an open top and sidewalls with sets of cooperating channels therein for receiving tape cassettes so as to be vertically insertable and removable relative to the tray. A system wherein a loader having a magazine with a plurality of vertically oriented tape cartridges therein is disclosed in Japanese Patent 2-96965, wherein the magazine is stationary and a reader is positioned over the magazine to remove a selected cartridge therefrom.
Known magazines for use in conventional loaders are typically open at a side thereof at which the data carriers are inserted and removed. When the magazine is not in the loader, however, it is desirable for the data carriers contained therein to be protected against dirt and damage to the data carriers which may arise during transport or storage of the magazine. Conventional magazines may therefore be provided with a manually removable cover, which can be placed over the opening, and which must be removed and set aside when the magazine is placed in the loader. It would be desirable to provide a magazine with a cover which is permanently attached thereto, however, this presents the problems of providing a mechanism in the loader for opening the cover, and providing room within the loader to accommodate the cover in its open position.